Meet William Herschel: Astronomer and Musician

sir william herschel
Astronomer and composer Sir William Herschel. His observational and musical contributions to science and art live on. National Portrait Gallery via Wikimedia Commons

Sir William Herschel was an accomplished astronomer who not only contributed volumes of work that astronomers use today, but also composed some pretty hip music for his time! He was a true "do-it-yourselfer", building more than one telescope during his career. Herschel was fascinated with double stars. These are stars in close orbits with each other, or that appear close to one another. Along the way, he also observed nebulae and star clusters. He eventually began publishing listings of all the objects he observed.

One of Herschel's most famous discoveries was the planet Uranus. He was so familiar with the sky that he could easily notice when something seemed out of place. He noticed that there was a dim "something" that seemed to move slowly across the sky. Many observations later, he determined it ws a planet. His discovery was the first one of a planet that had been noted since ancient times.  For his work, Herschel was elected to the Royal Society and made Court Astronomer by King George III. That appointment brought him income he could use to continue his work and build new and better telescopes. It was a good gig for a skygazer of any age! 

Early Life

William Herschel was born on November 15, 1738 in Germany and brought up as a musician. He began composing symphonies and other works as a student. As a young man, he worked as a church organist in England. Eventually his sister Caroline Herschel joined him. For a time, they lived in a house in Bath, England, which still stands today as a museum of astronomy. 

Herschel met up with another musician who was also a math professor in Cambridge and astronomer. That sparked his curiosity about astronomy, which led to his first telescope. His observations of double stars led to studies of multiple star systems, including the motions and separations of the stars in such groupings. He catalogued his discoveries and continued to search the skies from his home in Bath. Ultimately he ended up re-observing many of his discoveries again to check their relative positions. In Over time, he managed to find more than 800 new objects in addition to observing already-known objects, all using a telescope he built. Ultimately, he published three major listings of astronomy objects: Catalogue of One Thousand New Nebulae and Clusters of Stars in 1786, Catalogue of a Second Thousand New Nebulae and Clusters of Stars in 1789, and Catalogue of 500 new Nebulae, Nebulous Stars, and Clusters of Stars in 1802. His listings, which his sister also worked on with him, eventually became the basis for the New General Catalog (NGC) that astronomers still use today.

Finding Uranus

Herschel's discovery of the planet Uranus was almost entirely a matter of luck. In 1781, as he was continuing his search for double stars, he noticed that one tiny point of light had moved. He also noticed that it wasn't quite star-like, but more disk-shaped. Today, we know that a disk-shaped point of light in the sky is almost certainly a planet. Herschel observed it a number of times to make sure of his finding. Orbital calculations pointed to the existence of an eighth planet, which Herschel named after King George the III (his patron).  It became known as the "Georgian Star" for a time. In France, it was called "Herschel". Eventually the name "Uranus" was proposed, and that's what we have today. 

Caroline Herschel: William's Observing Partner

William's sister Caroline came to live with him after the death of their father in 1772, and he immediately had her join him in his astronomy pursuits. She worked with him to build telescopes, and eventually began doing her own observing. She discovered eight comets, as well as the galaxy M110, which is a smaller companion to the Andromeda Galaxy, and a number of nebulae. Eventually, her work caught the attention of the Royal Astronomical Society and she was honored by that group in 1828. After Herschel's death in 1822, she continued to do her astronomical observations and expand his catalogues. In 1828, she was also given an award by the Royal Astronomical Society. Their legacy of astronomy was carried on by William's son, John Herschel. 

Herschel's Museum Legacy

Herschel Museum of Astronomy in Bath, England, where he lived part of his life, remains dedicated to preserving the memory of the work done by William and Caroline Herschel. It features his discoveries, including Mimas and Enceladus (circling Saturn), and two moons of Uranus: Titania and Oberon. The museum is open to visitors and tours. 

There is a renaissance of interest in William Herschel's music, and a recording of his most popular works is available. His astronomy legacy lives on in the catalogs that record his years of observations.